English

Prepositions are the words which are used before the objects (nouns or pronouns). Preposition words connect nouns and pronouns with other parts of the sentence. Some of the examples of Prepositions are:

• He cleaned the shelf with a piece of cloth.
• I rushed into the room after seeing lizard.
• He sacrificed his life for his country.

In the above examples, with, into and for words are prepositions.

Composition or English Composition is the process and art of writing. It broadly refers to all kinds of writing including essays, reports, research papers, letters, stories, etc. 

The English Composition is broadly classified into four types, i.e. Narration, Description, Argumentation and Exposition. 

One-word substitutions are important in written English and here is why:

• It make the writing crisp. Long sentences can make writing appear chunky and the one-word substitutions simplify sentences without changing their meaning
• By using one-word for a particular concept avoids confusion
• They add sophistication to the language
• They are useful for academic writing and competitive exams  

Here are some of the advantages of using one-word substitution in English language:

• They replace long sentences or phrase with one word and make the sentence concise
• One-word substitutions expresses ideas accurately with fewer words
• They help in expanding the knowledge and improves written, verbal, and communication skills
• Also, One-word substitutions reduces word count without making the sentence lose its meaning

When a conjunction is used to connect two independent clauses, a comma should be used before the conjunction.

To conclude, conjunctions are vital to constructing well-formed sentences in English. Whether writing or speaking, using the right conjunctions will help one convey their message more clearly and effectively.

Yes, it is acceptable to begin a sentence with conjunctions like "but," "and," or "because," but they should be used sparingly.

Coordinating conjunctions connect clauses of equal grammatical weight (e.g., two independent clauses) whereas Subordinating conjunctions (like because, although, while) connect an independent clause to a dependent clause and show the relationship between them (cause, time, contrast, etc.).
Example (Coordinating): He was tired, yet he kept running.
Example (Subordinating): Although he was tired, he kept running.